Slow roasting on a Gene Cafe

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
StevensCoffee
Posts: 1
Joined: 11 years ago

#1: Post by StevensCoffee »

Hi there

I am the happy owner of a Gene Cafe coffee roaster. I have been roasting for about 2 years now, but have never been able to totally understand the "secrets" of the perfect roast. I understand that "the perfect roast" depends on personal taste an so, but i do think that a slow roast must be the ideal thing - or not?

I only roast coffee for filter brewing such as the v60, Chemex, Syphon and the mighty Aeropress.

I have tried many roast profiles, sadly no profile has ever resultet in beens nearly as tastefull as those i buy at my local roaster. Also, the profiles that people post around, typically aims at espresso-roast.

I always preheat the Gene, drying the beans for at 150C for about 5 minutes, and i cool external.

What do you guys do? What profile do you navigate around? I understand that no beans should be roastet the same way, but some sort of basic profile would be ideal.

Thank you so much.

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Boldjava
Posts: 2765
Joined: 16 years ago

#2: Post by Boldjava »

I have about 7 years on the Gene. I run it up to 350* to preheat with an E stop and add beans.

I roast at 464* through the start of 1st crack. (Setting varies with elevation at which bean was grown). At 1:00 past that start, I reduce the temp to 459* and take a roast to 2:30, 2:45, and 3:00 post initial 1st cracks and cup the differences in profiling. Note: I cool externally with a shop vac set-up.

Buy five pounds of a Guat, Colombian, or Costa Rican and vary your profiling. Cup until you find your sweet spot.

Note: Have two Genes. Temps are approx only as one runs hotter than the other at the same temp setting.
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JavaMD
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Joined: 11 years ago

#3: Post by JavaMD »

I roast on a Gene.

preheat to 325 F
E stop and drop in 227 gm of beans and warm them at 300 for 2 - 3 minutes
then crank up to 456 till first crack ... then once the first crack is going good will twist the dial down till the heater clicks off then twist it back up ... and repeat intermittently to help draw out the time between first and second crack so I can stop at city plus to full city which is usually what I'm aiming for. 14.5 to 15.5 % wt loss with the beans seems to be my target ...

if you have a bean grown at a lower elevation and don't want to heat is too fast then warm it for 3 - 4 minutes and while it is heating ... twist the dial down till the heater pops off and then twist it back on ... this does draw out the roast a bit ... often do this after beans turn brown from the yellow stage.

Lots of folks don't warm the beans at all ... and I've backed down from 5 minutes to 2-3 on that part of the profile. at 5 minutes the beans seemed to have a baked smell.

I've put temp probes in my Gene and can see what is happening to the temp ... one probe in the heater side and the other in the exhaust flow. Hook them up to my pc with RoasterThing software and Ira's datalogger which seems to work well.

Hope this helps ... but understand I don't claim at all to have the Gene roasting perfected ... Still on the journey ...
Steve

bmb
Posts: 343
Joined: 12 years ago

#4: Post by bmb »

I only have 75 roast in one year, but I read my share, used Roastmaster SW, also took notes and cupped all my roasts, and I managed to analyze all my curves.

The strategy I adopted is to simulate a Comercial roast, as near as possible.
Therefore I begin with an operationally heated roaster, that's about 220 to 230C.

For dense beans I'll do 5 minutes dehydrating phase at 220C, then crank up to 237 (looking for a 235C steady curve) to 240 (aiming at 239C).

When I smell that it's going from grassy to roast or pungent (you may also hear cracks ,watch bean expansion and chaff release) means it' beginning 1C, normally about 9 - 10 min, with dense beans.

I'll mark the time and will give about 1 - 2 min to finish the crack (expansion completed, color more even, smell more "roasty", less chaff release) and I'll go down to 225 (gradually, trying not to let it sink much below 225).

Then, by color and smell I'll wait another 3-4min and press the cooler. I'll leave it cooling for about 30 secs, till it gets to 180C and finish cooling outside.


For lower density beans it's the same preparation, begining also at 220, but dehydrating temp set at only 200C (May even be less for very delicate beans).
If beans are older (drier), only for 4 minutes or even less ...
Then I crank up to 234 (aiming at 232) to 237 (aiming at 235), with 1C happening with 7 -9 minutes.
The rest is about the same, I may go down a little with the finishing temp if the roast is going too fast.

I'm quite satisfied now as I finally arrived at my local roasters taste levels, and frequently even better.

BTW, have also been using a handheld digital "laser" thermometer, aiming at the beans and observed that temp beginning with 202 (1C) and going up to 215C during the roast.

The trick is not to pay attention to the instant temp (normally well under) but to the registered Max temp, that appears to have a quite approximate reading with what the Bean Temperature BT, should be at beginning of 1C.

Now, that I feel more confident and learned the taste of some roasted first class beans, I'm preparing myself to roast the higher end beans.